what if ichigo's dad previously did turn into FGT and challenge the Spirit King and lose his shinigami power before he actually finish off THAT King..aaaannndddd there kisuke was Son of the King..wait a minutes..where am i going..

I think Steel Dragon hit it on the head bro when he said that it is probably a chain link or something.

Also the Spirit King could just as easily exist outside reality and perception to be the stitches holding everything together. Squad Zero would essentially be adding their reiatsu constantly to hold the dimensions together.

I can't really think atm but didn't we see something about a Royal Family?